Electrical switch construction



Dec. 29, 1964 G. M. FARRELL 3,163,733

ELECTRICAL SWITCH CONSTRUCTION Filed June 1. 1961 0&5 0350 Q/J 0 o INVEN TOR. 629' M Farre/l 0W, won da, Wm %g United States Patent Ofiice 3,163,738 Patented Dec. 29, 1964 3,163,738 ELECTRICAL SWITCH CONSTRUCTION Guy M. Farrell, Elrnhurst, 111., assignor to F & F Enterprises, Inc., Chicago, Ill., a corporation of Illinois Filed June 1, 1961, Ser. No. 114,262 9 Claims. (Cl. 200-466) This invention relates in general to an electrical switch construction and more particularly to an improved switch arrangement of extremely small size.

Switches generally comprise a movable member which is arranged to be moved towards or away from another member to respectively close or open an electrical circuit. When the members are arranged to be normally closed they are known as break contacts and if normally open they are known as make contacts. In addition, the movable member commonly called an armature may be arranged to both open one circuit and close another by being moved from a break contact to a make contact. The members usually each comprise a flat cantilever spring. These are assembled in a stack with each separated from the other at one end by one or more insulators and that one end is held fixed while the other end of each armature is flexed or bent to establish or break an electrical connection. Such a stack is usually known as a spring or con-tact pile-up and often a number of armatures in such a stack are to be simultaneously operated.

Among the problems in the described switch construction is that of excluding dirt, securing alignment of the contacts and their closure under the required degree of spring pressure which in turn depends on the placement of each spring with respect to its mating or associated springs. This is further complicated by the need to provide a full stroke or movement of each armature among a plurality when only a first one is initially moved from some operating source and must transmit the force to the others which are not in direct association with the source. This is usually done by a bushing inserted between respective armatures for moving the succeeding armatures. In addition there are problems relating to the manufacture and assembly of such contact or spring pile-ups especially when they are limited in dimension such as those commonly known as micro switches.

It is accordingly an object of this invention to provide a contact pile-up in which dies of a common configuration may be used for fabricating both the insulators and the springs.

It is a further object of this invention to provide a contact pile-up in which the pile-up serves to guide a ram or bushings that permits the simultaneous actuation of all the contacts.

It is yet another object of this invention to provide contact assembly of small dimension from which environmental dirt is excluded.

It is a further object of the present invention to provide a contact pile-up which is capable of economic and facile manufacture and assembly.

Other objects together with the features of this invention will become apparent upon examination of the following specification, claims and drawings, wherein- FIG. 1 is a perspective view of the spring pile-up;

FIG. 2 is an enlarged perspective view of a portion of the pile-up;

FIG. 3 is a diagrammatic view illustrating the manner in which the contacts are arranged for operation;

FIGS. 4 and 4a illustrate the type of construction used for the insulators;

FIG. 4b illustrates the type of construction used in the springs;

FIG. 5 is a view through the line 55 in FIG. 4 illustrating the armature; and

FIG. 5a is a similar view to FIG. 5 illustrating either a make or break spring.

In FIG. 1 a contact or spring pile-up 10 is illustrated. This contact pile-up 10 comprises a sandwich construction in which a plurality of armature springs 18 are each separated from a respective break spring or contact 16 by the insulators 12, and from respective make contacts or springs 20 by the insulators 12 and 14. The insulators 14 differ from insulators 12 in thickness primarily and the number and thickness of the insulators is determined by the desired spacing between the springs. The contact pile-up is held in position by the rods 28 which are inserted through suitable recesses such as 26 provided in each of the insulators and springs. The rod ends are staked or otherwise fastened at the insulators 11 which are supplied at ends of the contact pile-up. The terminals whereby electrical connections are extended to the respective springs are indicated at 22.

As will be seen in FIG. 3, the contact pile-up 10 actually comprises a stacked array of make and break contacts with the armatures indicated at 18, the break springs indicated at 16 and the make spring at 20. The armatures 18 are operated by the pusher rod or ram 36 which is seen protruding from the stack in FIG. 1. The ram or bushing 30 engages a group'of serially arranged insulator rods or bushings 32 extending axially along the pile-up 10 as seen in FIGS. 1, 2 and 3. Each bushing 32 has a flange or car 34 adapted to engage a respective armature 18 and need not be fastened to the adjacent armature. The number of bushings 32 depends, of course, on the number of armatures to be operated.

Thus, the operation of the ram 30 either by a relay armature or other means transmits the operating pressure through each of the axially arranged rods 32 and through the flanges 34 to the respective armatures 18. During the operation of the rod 30 it will be noted that each of the flanges 34 flexes the armature 18 away from the projections 17 on the respective break contact 16 to open any circuit extended therethrough and closes the respective armature 18 to the projection 17 on the respective make contacts 20 to prepare or complete a circuit through that contact. During the flexing of the armature it will be noted that the armature 18 pivots and that ordinarily if it were carrying a bushing that bushing would be contacted by another spring at some intermediate point depending on the actual point of flexure of the armature 18. In the present arrangement, however, each of the flanges 34 simultaneously transmits the force from rod 30 to its adjacent armature at the same moment and at a similar point to simultaneously move all the armatures 18.

Turning now to FIGS. 4a, 4b, 5 and. 5a, the arrangement whereby this is accomplished will be seen. In FIGS. 4a and 4b it will be noted that both the springs 16, 18 and 20 and the insulators 12 and 14 are initially provided with an identical configuration. The configuration includes the rim portion 44 having the aperture 24 with the spaced apart recesses 26 and a tongue 27 on the springs and 29 on the insulators respectively. The recesses 26 accommodate the rods 28. In the case of the springs the tongue 27 serves as the contact spring. Thus the armatures 18 are simply used as shown in FIGS. 4b and 5, while if used as a break or make spring each is bent as shown at 17 in FIG. 5a to form the contact portion of the make or break spring 16 or 20. It will be seen that one die configuration may be used to stamp out both springs and insulators and by providing a projection 17 on the make or break springs and simply reversing the direction of that spring in the assembly 10 as shown in FIG. 2, those springs can serve in either capacity.

In the case of the insulator the terminal portion 45 and Waters 11.

the tongue 29 are simply broken ofl. as indicated by the dashed line in FIG. 4a. When assembled, the insulators and springs are stacked in succession as shown in FIGS. 1 and 2; The spring leaves are locked in position by the rods 28 which are formed of electrical insulating material and which are pressed through the aligned central recesses 26 and into the matching holes 35 in the end insulator In the preferred practice, the four outer recesses 36 are dimensioned to be larger than the. center recesses 26 to provide for greater flexibility in assembly whereby use can be made of metal eyelets for holding a single stack or several stacks together while still pro viding clearance between the metal eyelets and the spring leaves for electrically insulating one from the other. Protrusions can be provided in the molded insulating wafers 11, 12 and 14 to engage the recesses 26 at the center for purposes of effecting a more eifective alignment and rigid assembly. The insulating wafers 11, 12 and 14 are dimensioned to cover all of the edges of the spring leaves with the exception of the tabs 22 which are provided for electrical connection.

Thus the rods 28 are placed in position and the insulators 12 and 14 together with the springs 16, 18 and 20 are successively stacked thereon in the order shown. The rods 32 are each stacked or inserted with the respective flange 34 resting on a respective armature 18 which it is to operate. When an insulator 12, for example, is placed on an armature and the succeeding break spring assembled thereto, the bent portion 17 and the armature 18 prevent excessive lateral movement of the car 34 as shown in FIG. 2. The succeeding insulator holds ear 34 and the rod 32 in a position of abutment with the armature. The rod 30 is inserted in aperature 13 until it abuts the first rod 32 in the array so that a force transmitted thereto will operate the contacts, as explained. The rods 28 are staked or otherwise fastened to firmly and securely clamp the entire assembly for mounting in an appropriate position. The assembly illustrated in FIGS. 1 and 2 is one wherein the contacts are completely enclosed to exclude dirt. It

: requires extremely little space and as many as six make and break contacts may be stacked in approximately 1 inch with a width of about inch.

While the description has been addressed to arrangements wherein the flanges 34 displace armatures 18 from break contact to make contact, it will be understood that one or more of the armatures may be otherwise associated with the contacts for movement from one contact to the other. It will be also understood that the described assembly may be limited to a single double pole switch having but a single armature for displacement as well as to multiple switches arranged in a pile, as described.

Thus, having described one embodiment of my invention but believing it to be broader than the disclosed arrangement, there is appended hereto a series of claims whose scope is believed to more adequately cover the disclosed invention.

I claim:

'1. A spring contact assembly comprising a plurality of of'flat springs stacked one above the other and each having a portion protruding into a central aperture, an insulator arranged between each pair of successive springs, each of said insulators having a central aperture aligned with g the central aperture of said springs, and a movable actuator extending into said aperture and adapted to engage a said springs whereby said actuator is adapted to operate any of said portions either into or out of engagement with another porti'omand wherein the position of said actuator is maintained by said springs and an adjacent insulator without being fastened to either.

2. A spring contact assembly comprising a plurality of flat springs stacked one above the other and each having ;the central aperture of said springs, and a movable actuator extending into said aperture and adapted to engage said springs whereby said actuator is adapted to operate any of said portions either into or out of engagement with another portion, and wherein the protruding portion on one of said springs has a bent part, with said one spring being arranged to be either a make or break spring dependent on the direction in which said bent part extends in said assembly. 3. A spring contact assembly comprising a plurality o of fiat springs stacked one above the other and each having a portion protruding into a central aperture, an insulator arranged between each pair of successive springs, each ot said insulators having a central aperture aligned with the central aperture of said springs, and a movable actuator extending into said aperture and adapted to engage said springs whereby said actuator is adapted to operate any of said portions either into or out of engagement with another portion, each of said apertures having a configuration corresponding to that of a fastening rod extending through said assembly for preventing lateral movement of .tain the position of said actuator.

5. A spring contact assembly comprising a plurality of flat springs stacked one above the other with an insulator arranged between successive springs, each of said springs and insulators comprising a rim defining a central aperture, a tongue on each of said springs extending into said aperture, certain of said tongues having a bent end adapted to engage a respective adjacent tongue, others of said' tongues having a bent end adapted to be engaged by a respective one of the adjacent tongues, a rod for each adjacent tongue located in said aperture and having a flange for engaging the respective tongue, each rod axially aligned with an adjacent rod whereby a force applied to one of said rods enables all of the rods to move along.

flatsprings with an insulator between each spring, said insulators and springs each having an aperture aligned with the others, a plunger rod movably received in said apertures, said springs each having a tongue extending 7 into said aperture with one of said tongues adapted to engage said rod whereby movement of said rod flexes said one tongue to either engage the one tongue with another tongue or for disengaging said one tongue from another tongue. 4 i

8. A spring contact assembly comprising a plurality of flat springs stacked one above the other, insulators arranged between successive springs, each of said springs and insulators comprising a rim defining a central aperture, a tongue on each of said springs extending into said aperture, at least one of said springs comprising a'contact armature, the springsrabove and below said contact armature comprising make and break springs, the tongues on said make and break springs comprising bent ends extending toward the tongue on said contact armature and being adapted to engage said last mentioned tongue,

.at least one rod movably'positioned in said aperture .and' having a flange portion thereon for engaging the tongue of a contact armaturewhereby a force applied.

5 6 to said rod provides for flexing of the tongue of said conwhereby application of force to one of said rods enables tact armature away from one of said bent ends into conall of the rods to move axially to thereby switch the potact With the opposite bent end. sition of each of said contact armatures.

9. A contact assembly in accordance with claim 8 in- References cued in the file f this patent eluding a plurality of contact armatures each having a 5 make and break spring associated therewith, and includ- UNITED STATES PATENTS ing a plurality of axially aligned rods, each having 21 2,644,899 Perry July 7, 1953 flange portion for engaging one of said contact armatures 2,791,656 Dehn et al. May 7, 1957 

1. A SPRING CONTACT ASSEMBLY COMPRISING A PLURALITY OF OF FLAT SPRINGS STACKED ONE ABOVE THE OTHER AND EACH HAVING A PORTION PROTRUDING INTO A CENTRAL APERTURE, AN INSULATOR ARRANGED BETWEEN EACH PAIR OF SUCCESSIVE SPRINGS, EACH OF SAID INSULATORS HAVING A CENTRAL APERTURE ALIGNED WITH THE CENTRAL APERTURE OF SAID SPRINGS, AND A MOVABLE ACTUATOR EXTENDING INTO SAID APERTURE AND ADAPTED TO ENGAGE SAID SPRINGS WHEREBY SAID ACUTUATOR IS ADAPTED TO OPERATE ANY OF SAID PORTIONS EITHER INTO OR OUT OF ENGAGEMENT WITH ANOTHER PORTION, AND WHEREIN THE POSITION OF SAID ACTUATOR IS MAINTAINED BY SAID SPRINGS AND AN ADJACENT INSULATOR WITHOUT BEING FASTENED TO EITHER. 